Bioresorbable Scaffold Research Articles

Degrees of Inflammation in the Treatment of Subglottic Stenosis in a Rabbit Model: Histopathological Assessment of a Novel Bioabsorbable Ultra-high Ductility Magnesium Alloy Stent

ObjectiveUtilizing a novel histopathological scoring system and subglottic stenosis (SGS) rabbit model, we aimed to compare degrees of inflammation and severity of narrowing in the subglottis between two minimally invasive therapeutic modalities: endoscopic balloon dilation (EBD) alone versus EBD with placement of a bioabsorbable ultra-high ductility magnesium (UHD-Mg) alloy stent. MethodsSGS was induced endoscopically via microsuspension laryngoscopy in 23 New Zealand white rabbits. The control group (n = 11) underwent EBD alone, the study arm (n = 12) underwent EBD with implantation of bioabsorbable UHD-Mg alloy stents. Rabbits were euthanized at 2-, 3-, and 6-weeks after SGS induction, coinciding with wound healing stages. Using Optical Coherence Tomography (OCT), cross-sectional areas of airways were compared to calculate the mean percentage of intraluminal area at sequential time points. A novel histopathological scoring system was used to analyze frozen sections of laryngotracheal complexes. The degree of inflammation was quantified by scoring changes in inflammatory cell infiltration, epithelial ulceration/metaplasia, subepithelial edema/fibrosis, and capillary number/dilation. Univariate analysis was utilized to analyze these markers. ResultsWe found rabbits implanted with the bioabsorbable UHD-Mg alloy stent had statistically significantly higher scores in categories of hyperplastic change (stents vs controls: 1.48 vs 0.46 p < 0.001), squamous metaplasia (22 vs 5 p < 0.001), and neutrophils/fibrin in lumen (31 vs 8, p < 0.001). Rabbits who received EBD alone had higher scores of subepithelial edema and fibrosis (2.70 vs 3.49, p < 0.0256). The stented rabbits demonstrated significantly increased mean percent stenosis by intraluminal mean area compared to controls at 2 weeks (88.56 vs 58.98, p = 0.032), however at all other time points there was no significant difference between intraluminal subglottic stenosis by mean percent stenosis area. DiscussionRabbits with SGS treated with UHD-Mg alloy stents demonstrated histopathologic findings suggestive of lower levels of tracheal fibrosis. This could indicate a reduced tendency towards the development of stenosis when compared to EBD alone. There was not a difference in luminal size between stent and non-stented rabbits at the six-week end point. Histologically, however, overall the use of bioabsorbable UHD-Mg alloy stenting elicited a greater tissue response at the level of the superficial mucosa rather than fibrosis of the lamina propria seen in the stented rabbits. This suggests more favorable healing and less of a tendency towards fibrosis and stenosis even though there may not be a benefit from a luminal size standpoint during this early healing period. Compared to known complications of currently available non-bioabsorbable metal or silicone-based stents, this proof-of-concept investigation highlights the potential use of a novel biodegradable UHD-Mg stent as a therapeutic modality for pediatric SGS.

One-Month Dual Antiplatelet Therapy Followed by P2Y12 Inhibitor Monotherapy After Biodegradable Polymer Drug-Eluting Stent Implantation - The REIWA Region-Wide Registry.

The safety and feasibility of using 1-month dual antiplatelet therapy (DAPT) followed by P2Y12inhibitor monotherapy for patients after percutaneous coronary intervention (PCI) with thin-strut biodegradable polymer drug-eluting stents (BP-DES) in daily clinical practice remain uncertain.Methods and Results: The REIWA region-wide registry is a prospective study conducted in 1 PCI center and 9 local hospitals in northern Japan. A total of 1,202 patients who successfully underwent final PCI using BP-DES (Synergy: n=400; Ultimaster: n=401; Orsiro: n=401), were enrolled in the registry, and received 1-month DAPT followed by P2Y12inhibitor (prasugrel 3.75 mg/day or clopidogrel 75 mg/day) monotherapy. The primary endpoint was a composite of cardiovascular and bleeding events at 12 months, including cardiovascular death, myocardial infarction (MI), definite stent thrombosis (ST), ischemic or hemorrhagic stroke, and Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding. Based on the results of a previous study, we set the performance goal at 5.0%. Over the 1-year follow-up, the primary endpoint occurred in 3.08% of patients, which was lower than the predefined performance goal (Pnon-inferiority<0.0001). Notably, definite ST occurred in only 1 patient (0.08%) within 1 year (at 258 days). No differences were observed in the primary endpoint between stent types. The REIWA region-wide registry suggests that 1-month DAPT followed by P2Y12inhibitor monotherapy is safe and feasible for Japanese patients with BP-DES.

Symmetrical structure design of PLGA Biodegradable sinus stents and structure optimization based on surrogate models.

This study aims to enhance the degradation uniformity of PLGA sinus stents to minimize fracture risk caused by stress corrosion. Symmetric stent structures were introduced and compared to sinusoidal structure in terms of stress and degradation uniformity during implantation and degradation processes. Three surrogate models were employed to optimize the honeycomb-like structure. Results showed honeycomb-like structures exhibited the superior stress distribution and highest degradation uniformity. The kriging model achieved the smallest error and degradation uniformity of 83.24%. In conclusion, enhancing the symmetry of stent structures improves degradation uniformity, and the kriging model has potential for the optimization of stent structures.

Peripheral vascular bioresorbable scaffolds: Past, present, and future

As peripheral vascular disease affects more and more people in the world, interventional treatment of peripheral blood vessels evolves from percutaneous transluminal angioplasty to bioresorbable vascular scaffolds (BVS). At present, the materials of peripheral vascular bioresorbable scaffolds mainly include polymers and metal materials, and have achieved certain clinical application effects. Examples of these BVS are provided, and their advantages and defects are discussed. Poly-L-lactic acid is most commonly used in polymer BVS. There have been some polymer BVS entering clinical research for peripheral blood vessels since the 10 s, and have various outcomes. Metal materials for BVS mainly include magnesium alloy, iron alloy, and zinc alloy. The improved magnesium alloy BVS show excellent antiplatelet adhesion ability and can reduce the formation of acute stent thrombosis in clinical research. The iron alloy BVS and zinc alloy BVS also show excellent performance in animal experiments. The drug coating of BVS is expected to be improved. Finally, prospects of future development are highlighted. With the continuous improvement of manufacturing and drug-coating process, their therapeutic effect is expected to continue to improve.

Two-Year Outcomes for Patients with Non-ST-Elevation Acute Coronary Syndrome Treated with Magmaris and Absorb Bioresorbable Scaffolds in Large-Vessel Lesions.

The acute coronary syndrome (ACS) continues to be a fundamental indication for revascularization by percutaneous coronary intervention (PCI). Drug-eluting stent (DES) implantation remains a part of contemporary practice but permanent caging of the vascular structure with the metallic stent structure may increase the rate of device-related adverse clinical events. As an alternative to classic metallic DESs, the bioresorbable scaffolds (BRSs) have emerged as a temporary vascular support technology. We evaluated the mid-term outcomes of two generations of bioresorbable scaffolds-Absorb (Abbott-Vascular, Chicago, IL, USA) and Magmaris (Biotronik, Germany)-in patients with non-ST-elevation ACS. The study cohort consisted of 193 subjects after Magmaris implantation and 160 patients following Absorb implantation in large-vessel lesions. At 2 years, a significantly lower rate of a primary outcome (cardiac death, myocardial infarction, stent thrombosis) was observed with Magmaris (5.2% vs. 15%; p = 0.002). In addition, we observed a significantly lower rate of MI in the target vessel (2.6% vs. 9.4%; p = 0.009) and a lower rate of scaffold thrombosis (0% vs. 3.7%; p = 0.008). The TLF rate between the two groups was not significantly different. Magmaris demonstrated a good safety profile and more favorable clinical outcomes when compared to Absorb in patients with non-ST-elevation ACS.

In Silico Evaluation of In Vivo Degradation Kinetics of Poly(Lactic Acid) Vascular Stent Devices.

Biodegradable vascular stents (BVS) are deemed as great potential alternatives for overcoming the inherent limitations of permanent metallic stents in the treatment of coronary artery diseases. The current study aimed to comprehensively compare the mechanical behaviors of four poly(lactic acid) (PLA) BVS designs with varying geometries via numerical methods and to clarify the optimal BVS selection. Four PLA BVS (i.e., Absorb, DESolve, Igaki-Tamai, and Fantom) were first constructed. A degradation model was refined by simply including the fatigue effect induced by pulsatile blood pressures, and an explicit solver was employed to simulate the crimping and degradation behaviors of the four PLA BVS. The degradation dynamics here were characterized by four indices. The results indicated that the stent designs affected crimping and degradation behaviors. Compared to the other three stents, the DESolve stent had the greatest radial stiffness in the crimping simulation and the best diameter maintenance ability despite its faster degradation; moreover, the stent was considered to perform better according to a pilot scoring system. The current work provides a theoretical method for studying and understanding the degradation dynamics of the PLA BVS, and it could be helpful for the design of next-generation BVS.

REVASCULARIZATION WITHOUT DES: A CASE REPORT ABOUT METALLIC–LESS REVASCULARIZATION TECHNIQUES

Abstract Rational 56 years old patient, admitted to our service for myocardial infarction without ST elevation. In medical history he had dyslipidaemia, hypertension and familiarity for cardiovascular disease, without previous cardiological problems. The patient went to the ER for chest pain, started after his work shift. When admitted to the ER, the patient was still symptomatic for chest pain, with resolution after 3 hours after somministration of analgesics, with normal pressure and heart rate. An ECG was performed, without relevant findings, at the blood exams significative movement of cardiac troponins. At the echocardiogram apical hypokinesia of left ventricle with preserved ejection fraction. Technical Resolution Coronarography was performed, with evidence of severe diffuse atheromatic disease of the left anterior descending artery (LAD) at the proximal segment and sub–occlusive stenosis at the middle segment. Due to the diffuseness of the atherosclerotic disease on the LAD, which would have required a complete stenting of the artery, which using classical Drug Eluted Stents would have led to a complete metallization of the artery, in such a young patient who does not have medical history suggesting a progression of the atheromatic disease, metallic–less techniques were chosen. The two lesions were pre–dilatated with a non–compliant (NC) balloon. The proximal lesion was treated with a bioresorbable scaffold (BVS) Magmaris 3x25 mm, post–dilatated with a NC balloon, without complications. The distal segment was treated with a Drug Eluting Balloon (DEB) Pantera Lux 2.5x20 mm, expanded for 90 seconds, with evidence of focal dissection, not flow limiting.At the clinical follow–up performed at one and three months, the patient was asymptomatic for angina, without any cardiovascular event. Clinical Implications When facing coronaropathy in a young patient, it is a good option to treat the coronary with techniques that do not leave metallic material in the arteries, which exposes young patients to a higher rate of complications if compared to older patients. When it is preferred to use this kind of techniques, the options can be DEB or BVS. As seen in this case report, often the DEB can lead to complications. It’s well–known that every DEB complication needs a DES to fix it. However, little is proven and studied about the use of BVS on de–novo lesions and on coronary injuries as complications of “conventional” PCI, as well as those derived from DEB delivery.

Biodegradable tracheal stents: our ten-year experience with adult patients

BackgroundBiodegradable (BD) stents made from polydioxanone have been used only in human airways. These stents combine the advantages of classical tracheal stents, and fewer side effects are expected due to their biocompatibility and their time-limited presence in airways. However, new clinical consequences have arisen. Here, the authors share their experiences with BD stents for tracheal indications, focusing on their safety and efficacy.MethodsThis was a retrospective review of a collected database of adult patients who underwent implantation of biodegradable tracheal stents between September 2013 and December 2022 at the Department of Respiratory Medicine of the 1st Faculty of Medicine in Prague and Thomayer University Hospital. The indications included functionally significant nonmalignant tracheal stenosis and tracheomalacia. Self-expandable, biodegradable, polydioxanone tracheal stents manufactured by ELLA-CS Ltd. (Hradec Kralove, Czech Republic) were implanted during rigid bronchoscopy under general anaesthesia. All patients were followed up in the department and were provided with the necessary care. The main efficacy and safety parameters and relationships were analysed using descriptive statistics and Fisher´s exact, Wilcoxon and Kruskal‒Wallis tests.ResultsA total of 65 stents were implanted in 47 adult patients. During the first two months after implantation, when adequate function was expected, the stent was found to be effective in 26 out of 39 patients who completed this period (66.7%). The clinical effectiveness reached 89.7%, as early restenoses were mostly mild and necessitated treatment in only 4 patients. The frequencies of significant mucostasis, migration and granulation tissue growth were 2.6%, 7.5% and 23.1%, respectively, during this period. Thirty-four participants completed the half-year follow-up period after the first or second stent insertion, and some were followed up beyond this period. Poor control of symptoms, the development of restenosis and the need for interventions were characteristic of this period as the stents degraded. Twenty-two patients who experienced remodelling or stabilization of the tracheal lumen achieved a stent-free state. Seven patients underwent subsequent surgical treatment.ConclusionsBD stents are safe and provide adequate tracheal support until they begin to degrade. The use of BD stents necessitates close monitoring of patients and accurate treatment of possible restenosis.Trial registrationBased on project NT14146 – Biodegradable stents in the management of the large airways (2013–2015, MZ0/NT), registered on May 1, 2013, in the Research and Development and Innovation Information System of the Czech Republic and at ClinicalTrials.gov (reg. no. NCT02620319, December 2, 2015).

Thrombogenicity of biodegradable metals

Biodegradable metals offer a promising means to ameliorate many of the long-term risks associated with vascular devices made of conventional biostable stent metals. While numerous biodegradable metal alloys have been developed and characterized in animal models, knowledge of their blood reactivity and thrombogenicity remains unknown. Metal hemocompatibility is particularly valuable because current generation drug-eluting stents pose a significant long-term thrombosis risk. In this study, four pure metals, widely used as degradable base materials (Fe, Zn, Mg, and Mo), and three alloys commonly used in cardiovascular devices [NiTi, CoCr, and stainless steel (SS)] were evaluated. This work examined how each of these metals activate platelets, coagulation factors, and inflammation using in vitro hemocompatibility assays and a clinically relevant ex vivo non-human primate arteriovenous shunt model. Testing found that while all metals promoted a downstream activation of platelets and coagulation in flowing whole blood, platelet and fibrin attachment to Mg was markedly reduced. Additionally, Fe and Mo trended toward higher platelet attachment and contact pathway activation. Overall, the results suggest that Mg may delay clot initiation, but not eliminate clot formation, indicating the importance of understanding thrombosis in Mg alloys that are currently being developed for clinical use as biodegradable stents.

3D printed stents using Fused deposition modelling

3D printing has emerged as an appealing technology for designing and manufacturing bioresorbable stents. This innovative technology enables the creation of a diverse range of stent structures with specific features and intricate geometries, significantly impacting their mechanical properties and potentially affect clinical performance. In this study, we investigated the influence of various processing parameters during the 3D printing process and assess their effects on stent quality. Fused Deposition Modelling (FDM) was chosen as the 3D printing technology, with a focus on optimizing the printing of a novel chevron-strut stent design. Printing parameters were systematically investigated to understand their individual contributions to overall stent quality. The findings reveal the significance of print speed (6.5 mm/s) as a pivotal factor, influencing strut width and the difference between the Computer Aided Design (CAD) volume to calculated volume of stent. Furthermore, the optimization of printing parameters such as travel speed (200 mm/s), and line width (0.2 mm) led to the fabrication of stent with strut widths of 400 μm. However, it is important to also consider other parameters for comprehensive print optimization. In conclusion, by exercising control over the print process parameters, it becomes feasible to produce stents that closely align with the original CAD designs.

One-Year Outcomes of Biodegradable Polymer-Coated Sirolimus-Eluting Coronary Stent in Acute Coronary Syndrome: A Patient-Level Pooled Analysis from Two Indian Registries

Introduction: This pooled analysis was conducted to assess the clinical safety and performance of the Supra family (Sahajanand Medical Technologies Ltd., Surat, India) of sirolimus-eluting stents (SES) in patients with acute coronary syndromes (ACSs) including ST-segment elevation myocardial infarction (STEMI) from two real-world all-comers Indian registries at 1 year. Methods: We evaluated 1,824 patients with ACS who underwent percutaneous coronary intervention with the Supra family of SES from two real-world Indian registries (891 patients from T-Flex registry and 933 patients from Tetriflex real-world registry). The primary endpoint was the incidence of target lesion failure (TLF) defined as a composite of cardiac death, target-vessel myocardial infarction (TV-MI), and target lesion revascularization (TLR) at 1-year follow-up. The safety endpoint was stent thrombosis at 1-year follow-up. Results: Among a total of 1,824 patients with ACS, 689 (37.8%) patients presented with STEMI. In ACS and STEMI groups, 47.6% and 41.8% patients had multivessel disease, respectively. Of 2,128 lesions in ACS group, 76.7% lesions were type B2/C and 16.2% lesions were totally occluded. In the STEMI group, out of 784 treated lesions, 76.7% were type B2/C lesions and 21.9% were totally occluded. At 1-year follow-up, incidence of TLF was 5.3% (cardiac death: 0.9%, TV-MI: 2.5%, TLR: 1.9%) in patients with ACS and 6.2% (cardiac death: 1.4%, TV-MI: 2.1%, TLR: 2.7%) in patients with STEMI. The 1-year rate of definite/probable stent thrombosis was 0.3% and 0.7% in patients with ACS and STEMI, respectively. Conclusion: This patient-level pooled analysis provides evidence for the safe and effective use of the Supra family of SES in complex patient populations such as ACS and even in STEMI with favorable rates of TLF and stent thrombosis at 1-year follow-up.

Safety and efficacy of the latest generation biodegradable polymer-coated ultrathin sirolimus-eluting stent in the treatment of coronary artery disease in a European all-comer population with or without high bleeding risk: The Cruz HBR Registry.

The latest generation ultrathin Supraflex Cruz (Sahajanand Medical Technologies Limited, Surat, India) sirolimus-eluting stent (SES) has shown early healing properties and represents an attractive percutaneous coronary intervention (PCI) device in a high bleeding risk (HBR) population. The aim of this Cruz HBR registry was to assess safety and efficacy of the Supraflex Cruz SES in a large cohort of all-comer patients, of whom about one third were patients at HBR. Patients undergoing PCI were enrolled in this prospective, multi-centre, open label registry and stratified into non-HBR and HBR groups. The primary endpoint was a device-oriented composite endpoint (DOCE), a composite of cardiovascular death, myocardial infarction not clearly attributable to a non-target vessel and clinically driven target lesion revascularization within 12 months after PCI. The predefined aims were to show non-inferiority of the non-HBR group to the Supraflex arm of the TALENT Trial, and of the HBR group to polymer-free biolimus-coated stent arm of LEADERS FREE Trial. A total of 1203 patients were enrolled across 26 European centers, including a significant proportion (38.7%; N.=466) of HBR patients. A total of 1745 lesions were treated in 1203 patients and 2235 stents were implanted. The DOCE occurred within the total cohort in 5.8% of patients with a significant difference between HBR patients and non-HBR patients (8.1% vs. 4.4%; P<0.001). All-cause mortality at 12 months was significantly (P<0.0001) different among HBR (9.0%) and non-HBR patients (1.7%), respectively. At 12 months, the overall incidence of definite and probable stent thrombosis was 1.0%. Major bleeding occurred in 5.9% patients of the HBR group. These results met the non-inferiority criteria with respect to the TALENT trial for the non-HBR group (P<0.0001), and the LEADERS FREE trial for the HBR group (P<0.0001). The Cruz HBR registry confirms that PCI with the Supraflex Cruz SES is associated with a favorable clinical outcome in an all-comer population, including complex patients with HBR.

Bioabsorbable ureteral stents: current state-of-the-art

Ureteral stenting is one of the main methods for draining the upper urinary tract. The main drawbacks associated with the use of ureteral stents include high treatment costs, stent-associated symptoms, "forgotten" ureteral stents, encrustation, and polymer recycling after stent removal. Biodegradable ureteral stents may be solution for mentioned problems, offering several advantages: (1) avoidance of stent removal, reducing invasion procedures and health costs; (2) prevention of "forgotten" stents; (3) improvement of quality of life; (4) reduction in carbon footprint. This article presents a literature review of the recent developments in biodegradable stent technology.

Feasibility assessment of polyvinyl alcohol-based bioresorbable cardiovascular stents manufactured via solvent-cast direct writing extrusion

BackgroundBioresorbable stents represent a promising approach in cardiovascular interventions compared to drug-eluting stents. Additive manufacturing, particularly ink deposition, offers customization and versatility. This study delves into the potential of solvent cast direct-write 3D printing to fabricate cardiovascular stents using environmentally friendly solvents. MethodologyPolyvinyl alcohol, a biocompatible synthetic polymer that dissolves in water, was investigated as a suitable material for stent fabrication. The polymer was deposited on a rotating mandrel and subsequently crosslinked to establish a pseudostable state. Test specimens and stents were fabricated for characterization of both the material and stent dynamics. ResultsThis outcome is potentially suitable for deployment in the human body environment and adaptable to various biomedical applications, such as drug delivery patches or implants. The research optimized the fabrication of various stent geometries using polyvinyl alcohol and evaluated the kinetics of the working environment of these stents. Specifically, the 8-cell diamond stent showed remarkable characteristics, such as a high overexpansion of more than 0.5 mm, a compression force of 0.02 N and an elastic recovery of 88.85 %, with a strut thickness of 50.25 μm. Additionally, the study discusses the possibility of sterilizing polyvinyl alcohol with different methods, ethanol and autoclave were selected. ConclusionsThe results indicate that autoclaving leads to an increase in crystallinity. This yields a decrease in water absorption and an increase in mechanical properties. These results suggest that polyvinyl alcohol-based stents fabricated by solvent-cast direct writing are potential candidates for bioresorbable stent design.

Application of the Academic Research Consortium High Bleeding Risk criteria in patients treated with coronary bioresorbable polymer everolimus-eluting stents: Insights from the POEM trial

BackgroundPrevious studies have investigated a 1 to 6-month short dual antiplatelet therapy (S-DAPT) after percutaneous coronary intervention (PCI) with modern drug eluting-stents to reduce bleeding events. ObjectivesTo investigate cardiovascular outcomes in patients at high bleeding risk (HBR) according to the Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria after PCI with the Synergy bioresorbable-polymer everolimus-eluting stents (EES). MethodsWe applied ARC-HBR criteria in the population of the prospective, single-arm, multicenter POEM (Performance of Bioresorbable Polymer-Coated Everolimus-Eluting Synergy Stent in Patients at HBR Undergoing Percutaneous Coronary Revascularization Followed by 1-Month Dual Antiplatelet Therapy) trial. The primary endpoint was a composite of cardiac death, myocardial infarction, or definite or probable stent thrombosis at 12 months. ResultsThe original POEM cohort included 356 patients (80.4 %) fulfilling ARC-HBR criteria. Oral anticoagulant (OAC) usage and age ≥75 years were the most frequent major and minor ARC-HBR criteria, respectively. The ARC-HBR group was mainly represented by men (71.1 %), with 74.4 ± 9.3 years and a high burden of cardiovascular risk factors. DAPT was prescribed in 79.3 %, and single antiplatelet (SAPT) with OAC in 18.7 %. 12-month follow-up was completed in 96.2 %. The primary endpoint occurred in 5.2 % (95 % CI 3.29–8.10) of patients, whereas bleeding Academic Research Consortium type 3–5 occurred in 2.7 % (95 % CI, 1.39 %–5.05 %). ConclusionPrevious results of the POEM trial showed positive outcomes regarding ischemic and bleeding events with an S-DAPT regimen after Synergy EES. These results are also confirmed in sub-group analysis when ARC-HBR criteria are applied.

Mussel-Mimetic Hydrogel Coating with Anticoagulant and Antiinflammatory Properties on a Poly(lactic acid) Vascular Stent.

Biodegradable stents are the most promising alternatives for the treatment of cardiovascular disease nowadays, and the strategy of preparing functional coatings on the surface is highly anticipated for addressing adverse effects such as in-stent restenosis and stent thrombosis. Yet, inadequate mechanical stability and biomultifunctionality limit their clinical application. In this study, we developed a multicross-linking hydrogel on the polylactic acid substrates by dip coating that boasts impressive antithrombotic ability, antibacterial capability, mechanical stability, and self-healing ability. Gelatin methacryloyl, carboxymethyl chitosan, and oxidized sodium alginate construct a double-cross-linking hydrogel through the dynamic Schiff base chemical and in situ blue initiation reaction. Inspired by the adhesion mechanism employed by mussels, a triple-cross-linked hydrogel is formed with the addition of tannic acid to increase the adhesion and antibiofouling properties. The strength and hydrophilicity of hydrogel coating are regulated by changing the composition ratio and cross-linking degree. It has been demonstrated in tests in vitro that the hydrogel coating significantly reduces the adhesion of proteins, MC3T3-E1 cells, platelets, and bacteria by 85% and minimizes the formation of blood clots. The hydrogel coating also exhibits excellent antimicrobial in vitro and antiinflammatory properties in vivo, indicating its potential value in vascular intervention and other biomedical fields.

Unraveling the Enigma of Aortic Dissection: From Genetics to Innovative Therapies.

Aortic dissection (AD) presents a critical medical emergency characterized by a tear in the aortic wall, necessitating prompt recognition and management to mitigate catastrophic complications. Despite advancements in medical technology and therapeutic interventions, AD remains a formidable challenge, often resulting in severe morbidity and mortality. This narrative review provides a comprehensive overview of AD, encompassing its clinical presentation, diagnostic modalities, and management strategies, while also exploring emerging trends and innovations in its management. Genetic predispositions significantly influence AD pathogenesis, with over 30 contributory genes identified, emphasizing the importance of genetic screening and counseling. Classification systems such as Stanford and DeBakey, alongside their revised counterparts, aid in categorizing AD and guiding treatment decisions. Advancements in diagnostic imaging, including transesophageal echocardiography and computed tomography angiography, have enhanced diagnostic precision, augmented by artificial intelligence and machine learning algorithms. Pharmacological innovations focus on optimizing medical therapy, while surgical and endovascular approaches offer minimally invasive treatment options. Hybrid procedures and aortic valve-sparing techniques broaden treatment avenues, while bioresorbable stent grafts hold promise for tissue regeneration. Collaborative efforts and ongoing research are essential to address remaining challenges and improve outcomes in managing AD. This review contributes to the understanding of AD's complexity and facilitates informed decision-making in clinical practice, underscoring the imperative for continued innovation and research in AD management.

Bioresorbable Scaffolds for Below-the-Knee Arterial Disease: A Literature Review of New Developments.

This review aimed to explore the therapeutic effect of bioabsorbable stents in the inferior genicular artery, from the emergence of absorbable bare metal stents to the latest technology in polymer and anti-proliferative eluting drugs mixed with coated bioresorbable vascular stents (BVSs). Currently, there are conflicting data regarding the safety and effectiveness of BVSs in infrapopliteal artery interventions, especially compared to the current generation of drug-eluting stents (DESs). This review will cover the existing data on BVSs in reconstructing the infrapopliteal arterial blood flow and active clinical trials for future iterations of BVSs. In terms of primary patency rate and target lesion revascularization rate, the available research on the effectiveness of BVSs in reconstructing the infrapopliteal arterial blood flow suggests that a BVS is compatible with current DESs within 3-12 months; long-term data have not yet been reported. The ABSORB BVS is the most studied BVS in cardiovascular disease (CAD). Initially, the ABSORB BVS showed promising results. Managing intricate regions in peripheral artery disorders, such as branching or lengthy lesions, continues to be a formidable undertaking. In contrast to the advanced narrowing of arteries seen in standard permanent stent procedures, bioabsorbable stents have the potential to promote the expansion and beneficial merging of blood channels in the latter stages. Furthermore, incorporating stents and re-establishing the endothelial function can diminish the probability of restenosis or thrombosis. Nevertheless, the extent to which bioabsorbable stents may simultaneously preserve arterial patency and guarantee their structural integrity remains uncertain. The powerful and intricate mechanical stresses exerted by the blood in the superficial femoral artery and popliteal artery can cause negative consequences on any implant inserted into the vessel, regardless of its composition, even metal. Furthermore, incorporating stents is advantageous for treating persistent occlusive lesions since it does not impact later treatments, including corrective bypass operations. Evidence is scarce about the use of bioabsorbable stents in treating infrapopliteal lesions. Utilizing bioabsorbable stents in minor infrapopliteal lesions can successfully maintain the patency of the blood vessel lumen, whereas balloon angioplasty cannot offer this benefit. The primary focus of testing these materials is determining whether bioabsorbable scaffolds can provide adequate radial force in highly calcified elongated lesions. Indeed, using "-limus" medication elution technology in conjunction with bioabsorbable stents has previously offered clinical benefits in treating the popliteal artery, as evidenced by limited trials.BVSs for peripheral arterial disease (PAD) show promise and have the potential to offer a less inflammatory and more vessel-friendly option compared to permanent metallic stents. However, current evidence does not yet allow for a universal recommendation for their use. Thus, ongoing, and future studies, such as those examining the newer generation of bioresorbable scaffolds (BRSs) with improved mechanical properties and resorption profiles, will be crucial in defining the role of BRSs in managing PAD.

Solid-Phase Orientation (Die Drawing) of Polymer Tubes to Enhance Mechanical Properties of Bioresorbable Vascular Scaffolds

Die-drawing, also known as solid phase orientation, is a technique used to enhance the mechanical properties of polymers for non-medical applications [1]. Arterius has adapted and optimised this technology to manufacture state-of-the-art bioresorbable polymeric scaffolds (stents) based on polylactic acid (PLA) for vascular and non-vascular applications. The mechanical properties of the polymer are improved by orientating the polymer chains and introducing crystallinity to the polymer. As the PLA polymer is drawn over a mandrel and through a die, close to the glass transition temperature (Tg &gt; 55 °C), the polymer chains align, gradually increasing orientation with the bi-axial draw, thus promoting significantly improved mechanical properties. In-house testing of the die-drawn tubing compared to the extruded tubing showed an increase in tensile modulus up to 79.7%, yield strength increases of up to 121.5%, ultimate tensile strength increases of up to 267.9% and elongation at break increase of up to 1,022.8%. The die-drawing process also introduces crystallinity into the PLLA tubing, initially the amorphous extruded tube has a crystallinity of around 1.3% which increased to around 40% crystallinity after the die-drawn process. Another attribute of the orientated polymer tubing is the radial strength it provides to the scaffold once it has been laser cut into an innovative closed-cell design, which is comparable to market-leading metallic stents.

3D-printed bioresorbable vascular stents: emerging frontiers in personalized cardiac care

3D-printed bioresorbable vascular stents: emerging frontiers in personalized cardiac care